If you have a Mac then I'd also probably go with Final Cut Pro X (that's what I use the most), but especially if you're really into color correction you should check out DaVinci Resolve too. That would be my choice on Linux or windows.
I don't like editing in Resolve as much, but it's not too bad, and like iMovie there's a free version of Resolve that's still very capable. Both the professional version of Resolve and Final Cut cost $299.
There are some others out there like Sony Vegas, etc. and of course Adobe Premiere which was mentioned earlier, but I wouldn't go with Premiere unless you want to use other Adobe software and pay a fairly high monthly fee.